HI,
yesterday i fly my new zero g.s with a moki 210.
i do the break in trim the engine and go to the test flight.
as the airplane left the runway that engine have a cut but i landed the plane ok.
when i check the engine i notice that the prop is turning very hard.

i open the engien head to see if everthing is ok and everything is ok.

does anybody know this problem? how can i fix it?

thanks
nir

It sounds like the engine overheated....not good ! Are you using fuel with castor
oil in it ? Can you remove the cowling so more air and cooling can get to the
engine ?

FBD.

it was a test flight and without the cowl. i used omega 5%.

my problem is no the cut, my problem is that the engine is turning very hard.

do you have any idea whay?

You said you had removed the head from the engine to take a look. If there are
no scratches or visible damage inside the engine, and the engine is still hard to
turn over with the head off....I would guess that there is a problem with the
bearings....causing the tightness. It should turn over absolutely freely with the
head off. []

Dave.

The China Syndrome

i open the head again and there is nothing wrong there.

may be its need a little more break-in, i think that i will try to operate the engine again.

Make sure that you have proper air flow over the engine. Also make sure that it is tuned very rich for the first few gallons. It should not turn hard unless it's the compression causing it. Once it cools down, is it still hard to turn between compression? Should turn very freely between the compression spots.

im talking about a cool engine, i fly it yestarday

tzin:

I would advise pullig the back plate to check the rod bearing fit on the crank pin. This is a far more likely source of your stiffness than one of the ball bearings.

If the rod is tight it can be pulled out, the metal transferred to the crank pin can be removed, and possibly the rod will still be ok.

If you run the engine and the rod siezes fully the rod can break and destroy the engine completely.

Bill.

if your engine is to rich when new it can fill the crank case with fuel as cause it to hydralic and turn over hard even with the head off. if you have a regulater on it set the needle at 3 turn out and try it